6 Creedmoor: Review and load development

6 Creedmoor review and loads

A few years ago the movement towards 6.5mm match cartridges was in full swing, and while the 6.5 Creedmoor has gained a solid foothold, match shooters are now migrating to 6mm cartridges, one of which is the 6 Creedmoor.  The 6 Creedmoor is simply a 6.5 Creedmoor necked down to 6mm, shooting lower recoiling .243″ bullets.

Commonly encountered match cartridges, left to right: 6mm BR, 243 Winchester, 6x47 Lapua, 6 Creedmoor, 6.5x47 Lapua, 6.5 Creedmoor, 260 Remington, and 308 Winchester

Commonly encountered match cartridges, left to right: 6mm BR, 243 Winchester, 6×47 Lapua, 6 Creedmoor, 6.5×47 Lapua, 6.5 Creedmoor, 260 Remington, and 308 Winchester

Among the popular 6mm match cartridges, 243 Winchester, 6mm BR, 6×47 Lapua and 6 Creedmoor, the Creedmoor and Lapua are the most similar.  The 6mm BR is known to be a highly accurate cartridges, however, its relatively short length can present problems with the constant tension ejector found on Remington 700 style actions.  The Lapua and Creedmoor both feed and extract extremely well.  The biggest difference being between the two is the brass.  The Lapua uses a small rifle primer and Lapua brass (fairly expensive but excellent) while the Creedmoor uses a large rifle primer and Hornady brass (less expensive but not as good).  Note: As of August 2016, Lapua has announced plans to produce 6,5 Creedmoor brass.

Of the popular 6mm match cartridges, I’ve had great luck with 6mm BR, 6×47 Lapua and 243 Winchester, but decided it was time for a change, I had the reamer and brass so it was time to jump on the 6 Creedmoor bandwagon.

6 creedmoor rem 700 7

My test gun is a customized Remington 700 SPS Varmint that was had the factory barrel set back 1″ and rechambered.  The rifle started life as a 243 Win, but sometimes you need to chop a rifle up for science.  The barreled action sits in a Grayboe stock.  Grayboe is a new company, started by Ryan McMillan.  The Grayboe has the same shape as the McMillan A5  but costs significantly less.

The rifle uses the following parts:

WARNING: The loads shown are for informational purposes only.  They are only safe in the rifle shown and may not be safe in yours.  Consult appropriate load manuals prior to developing your own handloads.  Rifleshooter.com and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.

Load data for the 6 Creedmoor is fairly difficult to find.  Basically everyone says to shoot 42.0 grains of H4350 behind a 105 Hybrid or 107 SMK.  That’s it.  I spent hours and hours searching the web and calling various technical support lines, and that was all I could come up with.

This rifle is slightly different from most of the other 6 Creedmoors you’ll encounter.  This is because I am using a converted factory barrel with a slower twist (1:9 1/8″) as opposed to a 1:8″ twist on most custom rifles.  Keep in mind the barrel on this rifle is thinner than the #7/M40 profiles you’ll encounter on most custom guns.

I decided to approach load development with my two favorite 6mm bullets, the 107 grain Sierra MatchKing (SMK) and the 95 grain Sierra Tipped MatchKing (TMK).  For powder I selected H4350 since that is the most recommended powder I encountered (I also saw a couple references to RL17 without any supporting load data).

There are two ways to get brass for a 6 Creedmoor, you can either neck a 6.5 Creedmoor case down to 6mm, or you can buy it.  I bought a few hundred cases a couple of years ago from GAP when they were selling it.  At the time it was fairly exotic, however, the 6 Creedmoor is becoming more mainstream and I’ve seen brass for sale at a couple of different vendors.

6 creed 107 smk bullets with boxThe 107 SMK was 2.766″ to the lands.  I decided on a cartridge OAL of 2.750″ for testing, leaving a .016″ jump.

6 creed 95 TMK cartridges with box

The 95 TMK was 2.815″ to the lands.  I decided on a cartridge OAL of 2.800″, for a .015″ jump.

For testing and evaluation purposes all shooting was done prone, with a bipod, from a rear bag.   Velocity data was recorded with a MagnetoSpeed barrel mounted ballistic chronograph.

The number of shots for each group is recorded in the table below.  For the 107 SMK loads, I loaded five rounds in each powder charge.  Two rounds from the first 107 SMK load were used to zero the rifle.  Since the 95 TMK data was uncharted territory for me, I selected 3 and 4 shot groups- typically I avoid groups smaller than 5 rounds, however in this case I felt t was warranted.

6 creedmoor H4350 107 95 table

The 107 SMK seemed to prefer modest velocities between 2916 and 2943 feet/second.   Again at 3059 feet/second things looked pretty good.  The 42.0 grain load that most people love didn’t do so well in my gun, but looking at the same bullet and barrel when it was a 243, I saw a similar thing.

6 CREED 107 GROUP WITH BOX OF BULLETS

The 95 TMK looked very promising offering accuracy and low standard deviation with exceptional velocity (PRS shooters note that you cannot exceed 3,200 feet/second at a match).  The 43.5 grain load at 3,264 feet/second offers flat down range performance.  At 1,000 yards it has 6.8 mils of drop and 2.1 mils of drift in a 10 mile/hour crosswind.  Compare this to my 22″ 6.5 Creedmoor 142 SMK load with 9.3 mils of drop and 2.1 mils of drift or my 22″ 308 with a  175 SMK that has 11.2 mils of drop and 3.0 mils of drift.  I wish I had loaded 5 of each load but hindsight is 20/20.  Next trip to the range I’ll spend more time vetting the 95 TMK.

The 6 Creedmoor is a nifty 6mm match cartridge, it feeds and shoots well, offering shooters a capable option for their next match.

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